From what you described, I get the impression an SQL optimisation book is not what you need. Rather, try out whether a variant (e.g. SQLite, PostgreSQL) would suit your needs better (i.e. more easily, less painfully) than flat files do.

I don't know the scale nor expected use of your project, so it's hard to advise. SQL isn't that hard, yet it's powerful.

• A friendship (ID) could have two user(ID)s as its members, for instance.
• Top rated items would be selecting an x count of items sorted by their rating values in descending order.
• Indexes are fairly standard too.

Optimising seems more for your flat files design, given that you have more experience there. Using a routine to generate paths from IDs (as suggested earlier) would be a good way to start a benchmark schemes vs filesystem flavour and operating loads you expect to see.

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.